tried to parse string functions using constexpr in C++

F0:F030,F042,F072/usbcan_gpio/gpioproto.c

@@ -90,9 +90,11 @@ static const char* setCANspeed(char *buf){
     return sOKn;
 }
 
+#include "hashparser.h"
 static const char *cmd_parser(char *buf){
     if(!buf || !*buf) return NULL;
     if(strlen(buf) > 1){
+        chk(buf);
         // "long" commands
         char c = *buf++;
         switch(c){

F0:F030,F042,F072/usbcan_gpio/hashparser.cpp

@@ -0,0 +1,151 @@
+/*
+ * This file is part of the usbcangpio project.
+ * Copyright 2026 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+
+extern "C"{
+#include <stm32f0.h>
+#include "can.h"
+#include "flash.h"
+#include "hashparser.h"
+#include "gpioproto.h"
+#define USBIF   IGPIO
+#include "strfunc.h"
+}
+
+static const char *const sOKn = "OK\n", *const sERRn = "ERR\n";
+extern uint32_t Tms;
+
+// list of all commands and handlers
+#define COMMAND_TABLE \
+    COMMAND(canspeed,   "CAN bus speed setter/getter (kBaud, 10..1000)") \
+    COMMAND(dumpflash,  "flash config dump") \
+    COMMAND(time,       "Current time (ms)") \
+    COMMAND(help,       "Show this help")
+
+typedef struct {
+    const char *name;
+    const char *desc;
+} CmdInfo;
+
+// prototypes
+#define COMMAND(name, desc)   static errcodes_t cmd_ ## name(const char*, char*);
+    COMMAND_TABLE
+#undef COMMAND
+
+static const CmdInfo cmdInfo[] = { // command name, description - for `help`
+#define COMMAND(name, desc)   { #name, desc },
+    COMMAND_TABLE
+#undef COMMAND
+};
+
+static errcodes_t cmd_canspeed(const char *cmd, char _U_ *args){
+    SEND(cmd); PUTCHAR('='); SENDn(u2str(CAN_getspeed()));
+    if(args && *args){SEND("You entered: "); SENDn(args);}
+    return ERR_AMOUNT;
+}
+
+static errcodes_t cmd_dumpflash(const char _U_ *cmd, char _U_ *args){
+    SEND("userconf_sz="); SEND(u2str(the_conf.userconf_sz));
+    SEND("\ncurrentconfidx="); SENDn(i2str(currentconfidx));
+    for(int i = 0; i < InterfacesAmount; ++i){
+        SEND("interface"); PUTCHAR('0' + i);
+        PUTCHAR('=');
+        int l = the_conf.iIlengths[i] / 2;
+        char *ptr = (char*) the_conf.iInterface[i];
+        for(int j = 0; j < l; ++j){
+            PUTCHAR(*ptr);
+            ptr += 2;
+        }
+        NL();
+    }
+    SEND("canspeed="); SENDn(u2str(the_conf.CANspeed));
+    return ERR_AMOUNT;
+}
+
+static errcodes_t cmd_time(const char* cmd, char _U_ *args){
+    SEND(cmd); PUTCHAR('='); SENDn(u2str(Tms));
+    return ERR_AMOUNT;
+}
+
+static errcodes_t cmd_help(const char _U_ *cmd, char _U_ *args){
+    SEND(REPOURL);
+    for(size_t i = 0; i < sizeof(cmdInfo)/sizeof(cmdInfo[0]); i++){
+        SEND(cmdInfo[i].name);
+        SEND(" - ");
+        SENDn(cmdInfo[i].desc);
+    }
+    return ERR_AMOUNT;
+}
+
+constexpr uint32_t hash(const char* str, uint32_t h = 0){
+    return *str ? hash(str + 1, h + ((h << 7) ^ *str)) : h;
+}
+
+static const char* errtxt[ERR_AMOUNT] = {
+    [ERR_OK] =   "OK",
+    [ERR_BADPAR] =  "BADPAR",
+    [ERR_BADVAL] = "BADVAL",
+    [ERR_WRONGLEN] = "WRONGLEN",
+    [ERR_CANTRUN] = "CANTRUN",
+};
+
+
+// TODO: add checking real command length!
+
+void chk(char *str){
+    if(!str || !*str) return;
+    char command[CMD_MAXLEN+1];
+    int i = 0;
+    while(*str > '@' && i < CMD_MAXLEN){ command[i++] = *str++; }
+    command[i] = 0;
+    while(*str && *str <= ' ') ++str;
+    char *restof = (char*) str;
+    uint32_t h = hash(command);
+    errcodes_t ecode = ERR_AMOUNT;
+    switch(h){
+#define COMMAND(name, desc) case hash(#name): ecode = cmd_ ## name(command, restof); break;
+        COMMAND_TABLE
+#undef COMMAND
+        default: SEND("Unknown command, try 'help'\n"); break;
+    }
+    if(ecode < ERR_AMOUNT) SENDn(errtxt[ecode]);
+    ;
+}
+
+
+/*
+if(*args){
+    const char *n = getnum(args, &N);
+    if(n != args){ // get parameter
+        if(N >= CANMESG_NOPAR){
+            USB_sendstr(errtxt[ERR_BADPAR]); newline();
+            return RET_GOOD;
+        }
+        par = (uint8_t) N;
+    }
+    n = strchr(n, '=');
+    if(n){
+        ++n;
+        const char *nxt = getint(n, &val);
+        if(nxt != n){ // set setter flag
+            par |= SETTERFLAG;
+        }
+    }
+}
+*/

F0:F030,F042,F072/usbcan_gpio/hashparser.h

@@ -0,0 +1,34 @@
+/*
+ * This file is part of the usbcangpio project.
+ * Copyright 2026 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+// error codes for answer message
+typedef enum{
+    ERR_OK,         // all OK
+    ERR_BADPAR,     // wrong parameter
+    ERR_BADVAL,     // wrong value (for setter)
+    ERR_WRONGLEN,   // wrong message length
+    ERR_CANTRUN,    // can't run given command due to bad parameters or other
+    ERR_AMOUNT      // amount of error codes or "send nothing"
+} errcodes_t;
+
+// maximal length of command (without trailing zero)
+#define CMD_MAXLEN  (15)
+
+void chk(char *str);

F0:F030,F042,F072/usbcan_gpio/usbcangpio.creator.user

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE QtCreatorProject>
-<!-- Written by QtCreator 18.0.2, 2026-03-07T01:14:33. -->
+<!-- Written by QtCreator 18.0.2, 2026-03-08T01:14:58. -->
 <qtcreator>
  <data>
   <variable>EnvironmentId</variable>

F0:F030,F042,F072/usbcan_gpio/usbcangpio.files

@@ -8,6 +8,11 @@ gpioproto.c
 gpioproto.h
 hardware.c
 hardware.h
+hashgen/Readme
+hashgen/hashgen.c
+hashgen/mktestdic
+hashparser.cpp
+hashparser.h
 main.c
 ringbuffer.c
 ringbuffer.h

F0:F030,F042,F072/usbcan_gpio/version.inc

@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "85"
-#define BUILD_DATE "2026-03-07"
+#define BUILD_NUMBER "94"
+#define BUILD_DATE "2026-03-08"